Fragmented Prairies Make a Surprisingly Good Home for Deer Ticks

Photo credit: d_vdm/Creative CommonsDeer ticks, the tiny insects responsible for spreading Lyme disease and other ailments, favor forested habitats. There, they can easily pass from small mammals, birds, and lizards—on which they feed—to leaf litter and then deer, where they mate. The structure of this habitat seems so central to the tick's lifecycle that it has long been believed that it would have trouble spreading outside forests.

New research, however, has found deer ticks thriving in the fragmented prairie habitats of the Midwest, indicating that they may be far more versatile than previously thought.Researchers trapped small mammals in Illinois, collecting ticks from each one. Many of these ticks, they found, contained Lyme disease.

The landscape of Illinois, especially the northern and central area, is very fragmented with agricultural and other development, so there aren't really big continuous areas that are forested...and so maybe these ticks are finding new habitats to establish themselves in because of the lack of previous habitats.

Not only are the ticks finding new habitats, but new vectors as well. Instead of latching onto white-footed mice—as is common in forested areas—the majority of Lyme disease infected ticks and larvae in Illinois were found on prairie voles.

The voles are much less populous than white-footed mice. Those that were found, however, had a greater number of ticks attached to them. This increases the likelihood that the animals and ticks will carry Lyme disease in Illinois.

The findings, researchers say, are a call to think outside what is commonly thought about disease transmission.